'Yes, he will be allowed to land,' retired General Rashid Qureshi said, referring to Sharif's planned arrival at Lahore airport this afternoon on a chartered jet.

Musharraf ejected Sharif, whom he deposed as Prime Minister in a 1999 coup, from Pakistan when he tried to return last September. Four hours after landing in Islamabad, the politician was bundled onto a Saudi-bound airliner.

But the military ruler changed his mind last week after a meeting in Riyadh with King Abdullah. Qureshi said: 'Discussions were carried out on Sharif's return. The President said there is no issue; he can return if he wants to.'

His re-emergence is a potent addition to Pakistan's political cauldron, with Musharraf struggling to maintain power against a backdrop of instability and Islamist violence.

Yesterday two suicide bombers struck outside army headquarters in Rawalpindi, killing at least 35 people. One bomb hit an army checkpoint; the other a bus laden with employees from the Inter Services Intelligence agency. They were the first major attacks since Musharraf imposed emergency rule three weeks ago.

Musharraf, who insists he wants to become a civilian ruler, is under international pressure to lift the emergency and make good on promises to resign as head of the army.

Yesterday the national election commission cleared him to take the oath as a civilian President after the defeat of all legal challenges to his re-election. Qureshi said that Musharraf may take off his uniform as early as Tuesday.

Sharif is due to fly from Medina to Lahore in a plane chartered by the Saudi royal family, arriving at 5pm local time. That gives him long enough to file his nomination papers for the planned 8 January elections.

The drama underscores the weight of Saudi influence in Pakistan. Local media reported that Riyadh wanted Sharif, a conservative who, as Prime Minister, once tried to have himself titled 'Commander of the Faithful', to return as a counterweight to Benazir Bhutto, a relatively secular and liberal woman.